US Patent 11764120 Chip packaging structure and manufacturing method thereof

A chip packaging structure includes a chip, a redistribution layer, a solder ball, an encapsulant, and a stress buffer layer. The chip has an active surface and a back surface opposite to each other, and a peripheral surface connected to the active surface and the back surface. The redistribution layer is disposed on the active surface of the chip. The solder ball is disposed on the redistribution layer, and the chip is electrically connected to the solder ball through the redistribution layer. The encapsulant encapsulates the active surface and the back surface of the chip, the redistribution layer, and part of the solder ball. The stress buffer layer at least covers the peripheral surface of the chip. An outer surface of the stress buffer layer is aligned with a side surface of the encapsulant.